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LEONARD F. DUNN, OF ON EIDA COMMUNITY, NEW YORK.

PROCESS OF NICKEL-PLATING.

SPECIFICATION forming part of Letters Patent No. 278,784,"dated June 5,1883,

Application filed November 15, i882. (No specimens.)

To (.LZZ whom it ma concern.-

Be it known that LEONARD F. DUNN, of Oneida Community, in the county ofMadison, in the State of New York, have invented new and usefulImprovements in the Process of Nickel-Plating, of which the following isa full, clear, and exact description.

This invent-ion relates to an improved method of applying nickel-platingto iron or other inferior metal surfaces, whereby the said plating ismore firmly secured and rendered more durable than by any other knownprocess. In practice it has been found diificult to make nickel adhereto iron and other inferior metal, especially when used as a plating oftable-ware, such as knives, spoons, and forks, and other articles whichare liable to be bent or sprung. The nickel, being a very brittle metal,is unable to yield to the tension and compression incident to thebending or springing of the article to which it is applied as a coating,and consequently either peels off in large scales or flies off in a finedust when subjected to the aforesaid strains. To prevent this I placethe nickel-plating between two layers of silver, the former having agreat electrical adhesion for the latter, and the lat ter having atendency to firmly adhere to the article to be plated. The combinationof said three layers of metal formsa perfect tie, which securely fastensthe plating on the article to be plated, and by a certain degree oftheir amalgamation imparts to the nickel sufficient elasticity towithstand to a great extent the tension and compression incident to thebending or springing of the article plated therewith. To accomplish thisI first prepare the surface of the article to be plated in the usualmanner, then apply thereto a thin coating of silver, then apply to thesilver coating the nickel-plating to any desired thickness, and coverthe latter with another coating of silver, the successive coatings beingapplied by the ordinary electroplating process.

In practice I find it best to remove the article under treatment fromonebath to another instantaneously or without allowing the solution fromone bath to dry on the article so as to expose the metal surface to theatmosphere before introducing said article to the next bath. By thisprocess the silver adheres firmly to the surface of the article treated,the

nickel adheres firmly to the sih'ercoating, and the outside coating ofsilver sets firmly on the nickel-plating. The nickel-plating, being heldbetween two metals'of like electrical conditions, seems to amalgamate toa certain degree with its said inclosing coats, and thus becomepermanently united therewith. I- am able by this process to apply a muchheavier coating of nickel than by any other known process, thus givingto articles formed of inferior metals a surface which is hard anddurable and susceptible of fine polish.

Prior to my invention various methods have been resorted to for applyingprecious-metal plating to inferior metal articles. In one instance thenickel-coating has been applied directly to the inferior metal to form abase for the plating of superior metal.

In another case the finishing or preciousmetal plating was applieddirectly to the in ferior metal; and again in another case silver orother white metal capable of receiving a, high polish was applied to theinferior metal and highly burnished before applying thereto the hardfacing of nickel; but it is obvious that this latter process does notform as strong a tie between the metals as is obtained by pass ing thearticle under treatment from the silver bath directly to the nickel bathin the manner hereinbefore described. Neither has this peculiar methodever before been adopted; nor has the nickel-plating been inclosedbetween two layers of silver.

Having described my invention, what I claim as new, and desire to secureby Letters Patent, 1s

1. The process of securing nickel-plating to inferior metal, consistingin first applying to the latter a silver-coating and immediately passingit from the silver bath to the nickel bath, substantially as described.

2. The process of covering inferior metal with precious metal by firstapplying to the surface of the inferior metal a coating of silver, thenapplying to said silver the nickelplating, and subsequently covering thelatter with a silvercoating, substantially as described.

3. The process of covering inferior metal with precious metal by firstapplying to the surface of the inferior metal a coating of silver, thenapplying to the coating of silver a nickel plating, and finally coveringthe latter I of two attesting witnesses, at Syracuse, in the with asilver-coating, and in applying said county of Onondaga, in the State ofNew 10 successive coatings passing the article under I York, this 6thday of November, 1882. treatment from one bath to another Without T T T5 exposing the metal surfaces to the action of LEO} ARD DUAL theatmosphere, substantially as set forth. I Vitnesses:

In testimony whereof Ihave hereunto signed I F. H. GIBBS,

my name and affixed my seal, in the presence \VM. C. RAYMOND.

